1. Field of the Invention
This invention relates to methods and apparatus for feeding particulate solids into pressurized systems, and more particularly, to a method and apparatus for such feeding of particulate solids in which gas in one portion of the apparatus is transferred to another portion of the apparatus without significant loss of the gas.
2. Description Of The Prior Art
There are a number of applications in which particulate solids are moved into a pressurized system. For example, in alternate fuels processing using coal, oil shale, or the like, the introduction of solids into a high pressure reactor is necessary. A problem with prior devices is that this has not been possible without an accompanying loss of gas pressure from the reactor.
One solution has been to pressurize a rotary feeder from an external source so that chambers or passageways in the feeder are raised to substantially the same pressure as the pressurized system to which the solids are to be transferred. After transfer of the solids, the chambers or passageways are vented down to a lower pressure, such as atmospheric pressure, so that they may be refilled with the solids. Such apparatus are disclosed in U.S. Pat. No. 3,178,235 to Zimmermann and U.S. Pat. No. 2,858,212 to Durant et al. A problem with these prior art apparatus and other such systems is that they are not closed, and an outside pressure source must be utilized and renewed as necessary.
The present invention solves this problem by providing an essentially closed compression system which transfers gas from a chamber substantially empty of solids to a chamber which has been filled with solids. In this way, there is no significant loss of gas pressure from the pressurized system, such as the high pressure reactor in alternate fuels processing.